I'm not sure yet because I enjoy the combat aspect of mtg and other tcgs, but it's a sound idea to make the Win Condition dependent on creating the greatest amount of biodiversity. The idea I had is to have land cards (to borrow an mtg concept) and then build on top of that up the food chain. So for example your deck could be a Lake meta deck and begin with algae on turn 1 and work up to birds of prey or something.
Maybe you could direct your organisms to prey on other organisms of your opponent to interfere with them getting that wincon?? Still not sure.
One thing is for sure, I would want this to be a game where you have your deck and that's basically all you need. Wingspan is very cool and fun but it's definitely a board game; there's tons of things beyond the cards you need to physically play.